LP gas is easy and safe to store, which makes it a very portable fuel. It has been utilized for many different applications, some of which you've probably used yourself. Small, disposable butane lighters use the LP gas you are most likely to see on a daily basis. They contain a mixture of butane and isobutane.
If you have a portable gas grill, or if you go camping in a trailer or motor home, you use LP gas there, as well. The refillable gas tank on your grill uses propane, and the propane tanks on your motorhome can power a furnace, heat a hot-water tank or even power the refrigerator and freezer. Small tanks of camping fuel available at most sporting goods stores also use propane. The nozzles on the tanks have been standardized throughout the camping industry, so these tanks can be attached to camp stoves, lanterns, small water heaters and a variety of other devices.
Propane is useful in any situation where fuel is needed but it's not practical (or possible) to run lines for natural gas to the site. You can find LP gas on boats, at isolated cabins and hunting lodges or in rural areas that aren't served by commercial energy companies. In countries like India, where some large cities do not have reliable natural gas or other fuel service, LP gas makes up a major share of the energy market. Everyday heating and cooking needs are supplied by propane instead of oil or coal.
LP gas isn't only for home and leisure use, however. Many industries use LP gas as a source of heat for metal working, glass working or ceramics. Many industrial forklifts are LP-gas powered because LP gas provides enough power to do heavy lifting while generating reduced fumes and pollutants in confined warehouse spaces.
One of the fastest growing uses of LP gas is in automobiles. Cars built or converted to run on LP gas are becoming more and more common -- we'll find out why in the next section.